<?php

  use Drupal\Core\Datetime\DrupalDateTime;



  function buckeye_alert_preprocess_page(&$variables) {
    $config = \Drupal::config('buckeye_alert.buckeye_alert_config');

    $buckeye_alert_url = $config->get('buckeye_alert_url');
    $buckeye_alert_test = $config->get('buckeye_alert_test');
    $buckeye_alert_addl_date = $config->get('buckeye_alert_addl_date');
    $buckeye_alert_addl_expire = $config->get('buckeye_alert_addl_expire');
    $buckeye_alert_class = $config->get('buckeye_alert_class');
    $buckeye_alert_animate = $config->get('buckeye_alert_animate');
    $buckeye_alert_addl = $config->get('buckeye_alert_addl');

    //use the test feed if checked
    if ($buckeye_alert_test) {
      $url = '//www.osu.edu/feeds/alert-test/feed.rss';
    } else {
      $url = $buckeye_alert_url;
    }

    $additional_html = '';
    $now = new DrupalDateTime();
    if($buckeye_alert_addl_date !== null) {
      //get additional alert date and time
      $buckeye_alert_addl_date = new DrupalDateTime($config->get('buckeye_alert_addl_date'));
      //calculate expiration time
      $expires = new DrupalDateTime($config->get('buckeye_alert_addl_date'));
      $expires->add(new DateInterval('PT'.$buckeye_alert_addl_expire.'H'));
      //show additional message if the time has not expired
      if ($now >= $buckeye_alert_addl_date && $now < $expires) {
        $additional_html = $buckeye_alert_addl;
      }
    }

    //attach js libraries and pass drupal variables to dom
    $variables['#attached']['library'][] = 'buckeye_alert/buckeye_alert';
    $variables['#attached']['drupalSettings']['buckeye_alert']['feed_url'] = $url;
    $variables['#attached']['drupalSettings']['buckeye_alert']['messageClass'] = $buckeye_alert_class;
    $variables['#attached']['drupalSettings']['buckeye_alert']['animate'] = $buckeye_alert_animate;
    $variables['#attached']['drupalSettings']['buckeye_alert']['additional'] = $additional_html;
  }